<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>02边框的内间距</title>
    <style>
      .d1{
          width: 200px;
          height: 200px;
          background-color: #0aa1ed;
          border-radius: 100px;
      }
      .d2{
          width: 200px;
          height: 200px;
          border: 5px solid #f0f;
          padding-left: 50px;
          padding-top: 50px;
          box-sizing: border-box;
      }
      span{
          border: 3px solid #f00;
      }
      .s2{
          padding: 50px;
      }
    </style>

</head>
<body>
<div class="d1">边框测试</div>
<div class="d2">内间距测试</div>
<hr>
<span>我是span1</span>
<span class="s2">我是span2</span>
<span>我是span3</span>
</body>
</html>